The following abbreviations and terms are herewith defined, at least some of which are referred to within the following description of the present disclosure.
3GPP 3rd-Generation Partnership Project
AGCH Access Grant Channel
ASIC Application Specific Integrated Circuit
BLER Block Error Rate
BSS Base Station Subsystem
CC Coverage Class
CN Core Network
EC-GSM Extended Coverage Global System for Mobile Communications
EC-PCH Extended Coverage Paging Channel
eDRX Extended Discontinuous Receive
eNB Evolved Node B
DL Downlink
DSP Digital Signal Processor
EDGE Enhanced Data rates for GSM Evolution
EGPRS Enhanced General Packet Radio Service
GSM Global System for Mobile Communications
GERAN GSM/EDGE Radio Access Network
GPRS General Packet Radio Service
HARQ Hybrid Automatic Repeat Request
iDRX Intermediate Discontinuous Receive
IMSI International Mobile Subscriber Identity
IoT Internet of Things
LLC Link Layer Control
LTE Long-Term Evolution
MAR Mobile Autonomous Report
MCS Modulation and Coding Scheme
MME Mobility Management Entity
MS Mobile Station
MTC Machine Type Communications
NB Node B
N-PDU Network Protocol Data Unit
PCH Paging Channel
PDN Packet Data Network
PDTCH Packet Data Traffic Channel
PDU Protocol Data Unit
RACH Random Access Channel
RAN Radio Access Network
RAT Radio Access Technology
RTP1 Ready Timer Period 1
RTP2 Ready Timer Period 2
SGSN Serving GPRS Support Node
TDMA Time Division Multiple Access
TS Technical Specifications
UE User Equipment
WCDMA Wideband Code Division Multiple Access
WiMAX Worldwide Interoperability for Microwave Access
Coverage Class (CC): At any point in time a wireless device belongs to a specific uplink/downlink coverage class that corresponds to either the legacy radio interface performance attributes that serve as the reference coverage for legacy cell planning (e.g., a Block Error Rate of 10% after a single radio block transmission on the PDTCH) or a range of radio interface performance attributes degraded compared to the reference coverage (e.g., up to 20 dB lower performance than that of the reference coverage). Coverage class determines the total number of blind transmissions to be used when transmitting/receiving radio blocks. An uplink/downlink coverage class applicable at any point in time can differ between different logical channels. Upon initiating a system access a wireless device determines the uplink/downlink coverage class applicable to the RACH/AGCH based on estimating the number of blind transmissions of a radio block needed by the BSS (radio access network node) receiver/wireless device receiver to experience a BLER (block error rate) of approximately 10%. The BSS determines the uplink/downlink coverage class to be used by a wireless device on the assigned packet channel resources based on estimating the number of blind transmissions of a radio block needed to satisfy a target BLER and considering the number of HARQ retransmissions (of a radio block) that will, on average, be needed for successful reception of a radio block using that target BLER. Note: a wireless device operating with radio interface performance attributes corresponding to the reference coverage (normal coverage) is considered to be in the best coverage class (i.e., coverage class 1) and therefore does not make any additional blind transmissions subsequent to an initial blind transmission. In this case, the wireless device may be referred to as a normal coverage wireless device. In contrast, a wireless device operating with radio interface performance attributes corresponding to an extended coverage (i.e., coverage class greater than 1) makes multiple blind transmissions. In this case, the wireless device may be referred to as an extended coverage wireless device. Multiple blind transmissions corresponds to the case where N instances of a radio block are transmitted consecutively using the applicable radio resources (e.g., the paging channel) without any attempt by the transmitting end to determine if the receiving end is able to successfully recover the radio block prior to all N transmissions. The transmitting end does this in attempt to help the receiving end realize a target BLER performance (e.g., target BLER ≤10% for the paging channel).
eDRX cycle: eDiscontinuous reception (eDRX) is a process of a wireless device disabling its ability to receive when it does not expect to receive incoming messages and enabling its ability to receive during a period of reachability when it anticipates the possibility of message reception. For eDRX to operate, the network coordinates with the wireless device regarding when instances of reachability are to occur. The wireless device will therefore wake up and enable message reception only during pre-scheduled periods of reachability. This process reduces the power consumption which extends the battery life of the wireless device and is sometimes called (deep) sleep mode.
iDRX cycle: iDRX cycle determines the frequency with which a wireless device is reachable and a method for determining the specific radio blocks the wireless device reads to realize this reachability. The iDRX cycle is used upon returning to an idle mode and is only applicable while the ready timer is running. When the ready timer expires the wireless device reverts back to using the eDRX value it negotiated with the SGSN (using Non-Access Stratum (NAS) signalling).
Extended Coverage: The general principle of extended coverage is that of using blind transmissions for the control channels and for the data channels to realize a target block error rate performance (BLER) for the channel of interest. In addition, for the data channels the use of blind transmissions assuming MCS-1 (i.e., the lowest modulation and coding scheme (MCS) supported in EGPRS today) is combined with HARQ retransmissions to realize the needed level of data transmission performance. Support for extended coverage is realized by defining different coverage classes. A different number of blind transmissions are associated with each of the coverage classes wherein extended coverage is associated with coverage classes for which multiple blind transmissions are needed (i.e., a single blind transmission is considered as the reference coverage). The number of total blind transmissions for a given coverage class can differ between different logical channels.
Internet of Things (IoT) devices: The Internet of Things (IoT) is the network of physical objects or “things” embedded with electronics, software, sensors, and connectivity to enable objects to exchange data with the manufacturer, operator and/or other connected devices based on the infrastructure of the International Telecommunication Union's Global Standards
Initiative. The Internet of Things allows objects to be sensed and controlled remotely across existing network infrastructure creating opportunities for more direct integration between the physical world and computer-based systems, and resulting in improved efficiency, accuracy and economic benefit. Each thing is uniquely identifiable through its embedded computing system but is able to interoperate within the existing Internet infrastructure. Experts estimate that the IoT will consist of almost 50 billion objects by 2020.
Cellular Internet of Things (CIoT) devices: CIoT devices are IoT devices that establish connectivity using cellular networks.
Nominal Paging Group: The specific set of EC-PCH blocks a device monitors once per eDRX cycle. The device determines this specific set of EC-PCH blocks using an algorithm that takes into account its IMSI, its eDRX cycle length and its downlink coverage class.
Ready Timer: A timer started at a wireless device upon determining it has successfully transmitted a LLC PDU and started at the SGSN upon receiving a LLC PDU from that wireless device (i.e., the SGSN maintains device specific Ready Timer values).
An EC-GSM wireless device upon completing an uplink transmission will receive from the network (RAN node) an Extended Coverage Packet Uplink Ack/Nack (EC-PUAN) message which indicates that all the uplink data blocks have been received by the network (RAN node). The EC-PUAN message may also include an indicator which indicates that the EC-GSM wireless device is to enter an EC-GSM Idle mode or an EC-GSM Extended Uplink Temporary Block Flow (TBF) mode. In either mode, the EC-GSM wireless device will remain reachable for the remaining period of a ready timer, which was started after the EC-GSM wireless device's most recent successful transmission of an uplink LLC PDU (i.e., the most recent uplink transmission is confirmed by the EC-PUAN). However, the EC-GSM wireless device remaining reachable per the same periodicity of reachability (e.g., iDRX cycle length of 8 51-multiframes (˜1.9 seconds)) for the remaining period of the ready timer can be problematic given the battery-limited nature of the EC-GSM wireless device. This problem is addressed by the present disclosure.